A new study by Research Affiliates shows that even some growth stocks are too expensive even after including intangible assets. This according to a recent article in Institutional Investor.

“Mega-cap growth stocks, notably, the FANGs, still look expensive after incorporating intangibles in the value of firm capital,” according to a paper published by the firm after examining how intangible assets change the value calculation of companies (like the FANGs) with high levels of research and development expense—assets which are typically not included on company balance sheets and therefore don’t factor into traditional value metrics.

The study (which focused on Facebook, Amazon, Netflix and Google parent Alphabet) noted that intangibles now represent nearly all of the average firm’s tangible book value, versus 1963 when they represented about 30 percent of book value: “As intangible assets such as knowledge, intellectual property, and human capital become more important to firms’ successes, intangibles’ share of total company capital has grown meaningfully.”

But not all companies become a good deal after accounting for intangibles, the study found, noting that that Amazon, which had the highest R&D spending of any U.S. firm, remained pricey at nearly 4.5 times the price of the average company.

The study authors concluded that while “incorporating intangibles can make some growth firm valuations more reasonable, it will not change the fact that some companies are expensive today regardless of the metric used to evaluate them.”